基于高精度点云的密封平面装配质量评价

Assembly Quality Evaluation of Sealing Planar Based on High Precision Point Cloud

密封平面在工业现场中有重要的应用,为保证其密封性必须要严格控制密封平面的加工及装配质量。旨在通过密封性来评价密封平面的装配质量,同时要满足密封平面装配质量评价对高精度、高效、可视化的要求,提出一种基于高精度点云数据采用中轴变换对密封平面进行装配质量评价的方法。首先利用High-definition metrology(HDM)系统获取密封平面上的高精度点云数据,点云要保留波纹度特征;然后依据密封平面的装配定位基准对点云进行配准;最后基于中轴变换模拟密封平面上的泄漏通道,从而对密封平面的装配质量进行评价。对如何通过中轴变换法提取泄漏通道进行了研究,并对点云数据在法矢量估计中的快速定向方法进行了改进。为验证该方法的有效性,以某泄漏内燃机的缸体缸盖结合面为例进行了试验,结果证明该方法可以准确识别泄漏的位置并能够基于不同的分割阈值模拟泄漏通道的形状,说明该方法可以对密封平面的密封性进行定性、定量的理论预报和评价。

The sealing plane has an important application in the industrial field. To ensure seal, its machining and assembly quality must be strictly controlled. In order to evaluate the assembly quality of the sealing plane in an accurate, efficient and visual way from the perspective of sealing performance, a new method, based on the high-precision point cloud is presented, using the medial axis transform(MAT) to evaluate the quality of seal plane assembly method. First, based on high-definition metrology(HDM) obtains the high-precision point cloud data of sealing planar that is with waviness characteristics, and then registers the point cloud data according to the assembly location and position of the parts. Finally, based on the MAT, calculate the leakage channel of sealing planar, so that the assembly quality of the sealing planar can be evaluated. It focuses on the study of using MAT to calculate leakage channel, and improves the fast orientation method of the point cloud data in the normal vector estimation. In order to verify the effectiveness of the method proposed, a verification experiment was conducted on the head deck faces of a leaking engine block and a cylinder head. The results show that the proposed method can accurately identify the location of the leak and simulate the shape of the leak channel based on different segmentation thresholds. This method can make qualitative and quantitative theoretical predictions and evaluations on the seal plane sealing performance.